Systems and Methods for Low Power RF Data Reception

ABSTRACT

Systems and methods are disclosed for low power RF communications, comprising receiving an AM signal using a passive RF receiver circuit, converting the AM signal to a digital output signal using a comparator, receiving the digital output signal from the comparator, determining whether the digital output signal is valid or not using a digital signal processing circuit, and upon detection of a valid digital output signal, enabling an active RF receiver circuit for RF signal processing.

TECHNICAL FIELD

The present disclosure is generally related to communications and, moreparticularly, is related to low power RF data reception.

BACKGROUND

Generally, most portable radio frequency (RF) devices such as stereoremotes and cordless telephones are battery operated. As many users ofportable RF devices may appreciate, portable is often synonymous withlost and/or misplaced. Some wireless devices include a locate/pagefeature, whereby the misplaced device will flash and/or emit an alarmsound in response to a signal from a base station or charging dock.Unfortunately, the locate/page feature will not work if the misplaceddevice has run out of battery power.

One reason battery powered devices run out of power can be attributed tothe fact that many battery powered devices utilize active reception ofRF signals. A drawback to this approach is that active reception of RFsignals presents a relatively high power drain to the battery poweringthe device. To compound the matter, the aforementioned relatively highpower drain is also relatively constant, thereby depleting battery powereven faster. There are heretofore unaddressed needs with previous lowpower RF solutions.

SUMMARY

Example embodiments of the present disclosure provide a method forproviding RF data reception. One embodiment of such a method, amongothers, can be broadly summarized as receiving an amplitude modulated(AM) signal using a passive RF receiver circuit, converting the AMsignal to a digital output signal using a comparator, determiningwhether the digital output signal is valid or not using a digital signalprocessing circuit, and upon detection of a valid digital output signal,enabling an active RF receiver circuit for further RF signal processing.

Embodiments of the present disclosure can also be viewed as providingsystems for supporting provision of RF data reception. Brieflydescribed, in architecture, one example embodiment of the system, amongothers, can be implemented as follows: a passive receiver configured toreceive an AM signal using a passive RF receiver circuit, a comparatorconfigured to convert the AM signal to a digital output signal, and aprocessor comprising a computer-readable medium with a set ofinstructions operable to receive the digital output signal from thecomparator, determine whether the digital output signal is valid or notusing a digital signal processing circuit, and upon detection of a validdigital output signal, enable an active RF receiver circuit for furtherRF signal processing.

According to still yet another embodiment of the present disclosure,example embodiments of the present disclosure for supporting provisionof RF data reception include a passive RF receiver circuit for receivingan AM signal, a comparator for converting the AM signal to a digitaloutput signal, a digital signal processing circuit for determiningwhether the digital output signal is valid or not, and a switch foractivating an active RF receiver circuit for further RF signalprocessing upon detection of a valid digital output signal.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 provides a system block diagram of an example embodiment of asystem for supporting provision of low power RF data reception.

FIG. 2 provides a system block diagram of another example embodiment ofa system for supporting provision of low power RF data reception.

FIG. 3 provides a diagram of an example embodiment of a transmitter forsupporting provision of RF data transmission.

FIG. 4 provides a flow diagram of an example embodiment of a method forproviding low power RF data reception.

DETAILED DESCRIPTION

Embodiments of the present disclosure will be described more fullyhereinafter with reference to the accompanying drawings in which likenumerals represent like elements throughout the several figures, and inwhich example embodiments are shown. Embodiments of the claims may,however, be embodied in many different forms and should not be construedas limited to the embodiments set forth herein. The examples set forthherein are non-limiting examples and are merely examples among otherpossible examples.

It is to be understood that the following disclosure provides manydifferent embodiments, or examples, for implementing different featuresof various embodiments. Specific examples of components and arrangementsare described below to simplify the present disclosure. These are, ofcourse, merely examples and are not intended to be limiting. Inaddition, the present disclosure may repeat reference numerals and/orletters in the various examples. This repetition is for the purpose ofsimplicity and clarity and does not in itself dictate a relationshipbetween the various embodiments and/or configurations discussed.Moreover, the formation of a first feature over or on a second featurein the description that follows may include embodiments in which thefirst and second features are formed in direct contact, and may alsoinclude embodiments in which additional features may be formedinterposing the first and second features, such that the first andsecond features may not be in direct contact.

In the following description, numerous details are set forth to providean understanding of the present disclosure. However, it will beunderstood by those of ordinary skill in the art that the presentdisclosure may be practiced without these details and that numerousvariations or modifications from the described embodiments may bepossible. The disclosure will now be described with reference to thefigures, in which like reference numerals refer to like, but notnecessarily the same or identical, elements throughout. For purposes ofclarity in illustrating the characteristics of the present disclosure,proportional relationships of the elements have not necessarily beenmaintained in the figures.

Referring now to the drawings in which like numerals represent likeelements or steps throughout the several views, FIG. 1 provides a systemblock diagram of an example embodiment of a system for supportingprovision of low power RF data reception via receiver 100. Receiver 100includes antenna 110, RF notch filter 120, AM demodulator 130, ACcoupler 140, low power comparator 150 and low power signal processor160.

Antenna 110, RF notch filter 120, AM demodulator 130, and AC coupler 140comprise a passive RF receiver circuit that does not utilize anyDC/battery power. According to some non-limiting example embodiments,antenna 110 may include a coil antenna, crystal receiver, or othersensitive device. RF notch filter 120 may include one or more resistors,capacitors, and inductors. AM demodulator 130 may include one or morediodes, capacitors, and resistors. AC coupler 140 may connect thepassive RF receiver circuit to comparator 150 and signal processor 160.Comparator 150 and digital signal processor 160 may utilize DC powerfrom battery 155.

In operation, an AM signal is received over antenna 110 and passedthrough RF notch filter 120. The signal passes through RF notch filter120, is demodulated via AM demodulator 130, and then passed tocomparator 150 to convert the signal to a digital format. The output ofcomparator 150 is then passed to digital signal processor 160. It shouldbe noted that digital signal processor 160 may utilize one or moreencryption techniques in order to determine if the signal is valid ornot. In an example embodiment, the signal is coded with an algorithm toreduce the likelihood of being triggered by random or non-random noisesuch as use of a rotating Cyclic Redundancy Code (CRC) with a randomnumber that is not repeated.

Signal processor 160 (which, in an example embodiment is a low powersignal processor) is connected, via switch 170, to active RF receiver180 and signal processor 190 (which, in an example embodiment is arelatively higher power signal processor). When a valid signal isdetected, signal processor 160 activates active RF receiver 190 viaswitch 170. Once toggled, switch 170 activates high level signaldetection under certain conditions by providing power to active RFreceiver 180 and signal processor 190. Active RF receiver 180 thenreceives the RF signal using one or more RF processing techniques. Itwill be appreciated that active RF receiver 180 may utilize a range ofmodulation techniques. Once the signal is detected as valid, a requestedprocess may be executed (e.g. for a lost remote control, to sound abeep). Additionally, it will be appreciated that in some embodimentscertain coding techniques are employed to minimize false activation ofthe active RF circuitry.

It will be appreciated that receiver 100 may provide RF reception forany number of portable devices including but not limited a computer,remote control, cordless telephone, smart phone, wireless lock, DVR andthe like. Active RF receiver 180 may include one or more circuit typesincluding heterodyne, super heterodyne and the like. Additionally,active RF receiver 180 may employ one or more techniques includingautomatic gain control, squelch, or other sophisticated modulationtechniques.

FIG. 2 provides a system block diagram of another example embodiment ofa system for supporting provision of low power RF data reception viareceiver 200 according to an example embodiment of the disclosure.Receiver 200 includes antenna 210, RF notch filter 220, AM demodulator230, AC coupler 240, comparator 250 and signal processor 260. As withFIG. 1, antenna 210, RF notch filter 220, AM demodulator 230, and ACcoupler 240 comprise a passive RF receiver circuit that does not utilizeany DC/battery power.

Signal processor 260 (which, in an example embodiment is a low powersignal processor) is connected, via switch 270, to active RF receiver280 and signal processor 290 (which, in an example embodiment is arelatively higher power signal processor). When a valid signal isdetected, signal processor 260 activates active RF receiver 280 viaswitch 270. Once toggled, switch 170 activates high level signaldetection under certain conditions by providing power to active RFreceiver 280 and high power signal processor 290. Active RF receiver 280then receives the RF signal using one or more RF processing techniquesover antenna 210 via RF notch filter 285. It will be appreciated thatwhile RF notch filter 285 is depicted as a separate component, in anexample embodiment in accordance with the present disclosure, active RFreceiver 280 circuit may include a filter, such as a notch filter,internally. RF notch filter 285 may be an active filter utilizing thesame DC power as active RF receiver 280

An alternative embodiment of the reception by the passive receiver ofantenna 210, RF notch filter 220, AM demodulator 230, AC coupler 240,comparator 250 and signal processor 260 involves two stages. In a firststage, a simple RF message is received that “wakes up” the device. In asecond stage, a higher level RF message is received, the higher level RFmessage containing more information, such as a non-limiting example ofconfiguration information. The two message may be transmitted on thesame frequency or on different frequencies. In an example embodiment,the two stages utilize different modulation methods.

The software instructions processed on signal processor 280 and signalprocessor 290 may be stored on a computer readable medium. As usedherein, the term “computer-readable medium” may describe any form ofmemory or a propagated signal transmission medium. Propagated signalsrepresenting data and computer program instructions may be transferredbetween network devices and systems. Embodiments of computer-readablemedia include, but are not limited to, electronic, flash, optical,magnetic, or other storage or transmission devices capable of providinga processor with computer-readable instructions. Also, various otherforms of computer-readable media may transmit or carry instructions to acomputer, including a router, private or public network, or othertransmission device or channel, both wired and wireless. Theinstructions may comprise code from any computer-programming language,including, for example, C, C++, C#, Visual Basic, Java, Python, Perl,and JavaScript.

Example environment 100 shown in and described with respect to FIGS. 1and 2 is provided by way of example only. Numerous other operatingenvironments, system architectures, and device configurations arepossible. Other system embodiments can include fewer or greater numbersof components and may incorporate some or all of the functionalitydescribed with respect to the system components shown in FIGS. 1 and 2.

FIG. 3 provides a diagram of an example embodiment of transmitter 300for supporting provision of RF data transmission. As shown in FIG. 3,transmitter 300 comprises random number generator 310, which generatesnonce 320 (single use random number). In an example embodiment, randomnumber generator 310 is a pseudo random number generator. Nonce 320 isencoded into baseband signal 340 by coding algorithm module 300.Baseband signal 340 is sent to AM transmitter 350, which produces AMmodulated signal 360. AM modulated signal 360 is broadcast via antenna370 for RF reception by any number of RF devices including receivers 100and/or 200. In an example embodiment one or more encryption techniquesmay be used in coding algorithm module 330. For example, according to anexample embodiment, coding algorithm module 330 produces encryptedbaseband signal 340 to include nonce 320 followed by one or more values,where the values are known to both transmitter 300 and receiver(s) 100,200.

FIG. 4 provides a flow diagram of an example embodiment of a method forproviding low power RF data reception in accordance with an exampleembodiment of the disclosure. In block 402, a low level AM signal isreceived using a passive RF receiver circuit. In block 404, the AMsignal is converted to a digital output signal using a comparator isshown. In block 406, the instruction to receive the digital outputsignal from the comparator and the digital output signal is determinedas valid or not using a digital signal processing circuit. In block 408,upon detection of a valid digital output signal, an active RF receivercircuit is enabled for high level RF signal processing.

The flow diagram of FIG. 4 shows the architecture, functionality, andoperation of a possible implementation of low power RF data reception.In this regard, each block represents a module, segment, or portion ofcode, which comprises one or more executable instructions forimplementing the specified logical function(s). It should also be notedthat in some alternative implementations, the functions noted in theblocks may occur out of the order noted in FIG. 4. For example, twoblocks shown in succession in FIG. 4 may in fact be executedsubstantially concurrently or the blocks may sometimes be executed inthe reverse order, depending upon the functionality involved. Anyprocess descriptions or blocks in flow charts should be understood asrepresenting modules, segments, or portions of code which include one ormore executable instructions for implementing specific logical functionsor steps in the process, and alternate implementations are includedwithin the scope of the example embodiments in which functions may beexecuted out of order from that shown or discussed, includingsubstantially concurrently or in reverse order, depending on thefunctionality involved. In addition, the process descriptions or blocksin flow charts should be understood as representing decisions made by ahardware structure such as a state machine.

Any process descriptions or blocks in flow charts should be understoodas representing modules, segments, or excerpts of code which include oneor more executable instructions for implementing specific logicalfunctions or steps in the process, and alternate implementations areincluded within the scope of the example embodiments in which functionsmay be executed out of order from that shown or discussed, includingsubstantially concurrently or in reverse order, depending on thefunctionality involved. In addition, the process descriptions or blocksin flow charts should be understood as representing decisions made by ahardware structure such as a state machine.

The logic of the example embodiment(s) can be implemented in hardware,software, firmware, or a combination thereof. In example embodiments,the logic is implemented in software or firmware that is stored in amemory and that is executed by a suitable instruction execution system.If implemented in hardware, as in an alternative embodiment, the logiccan be implemented with any or a combination of the followingtechnologies, which are all well known in the art: a discrete logiccircuit(s) having logic gates for implementing logic functions upon datasignals, an application specific integrated circuit (ASIC) havingappropriate combinational logic gates, a programmable gate array(s)(PGA), a field programmable gate array (FPGA), etc. In addition, thescope of the present disclosure includes embodying the functionality ofthe example embodiments disclosed herein in logic embodied in hardwareor software-configured mediums.

Software embodiments, which comprise an ordered listing of executableinstructions for implementing logical functions, can be embodied in anycomputer-readable medium for use by or in connection with an instructionexecution system, apparatus, or device, such as a computer-based system,processor-containing system, or other system that can fetch theinstructions from the instruction execution system, apparatus, or deviceand execute the instructions. In the context of this document, a“computer-readable medium” can be any means that can contain, store, orcommunicate the program for use by or in connection with the instructionexecution system, apparatus, or device. The computer readable medium canbe, for example but not limited to, an electronic, magnetic, optical,electromagnetic, infrared, or semiconductor system, apparatus, ordevice. More specific examples (a nonexhaustive list) of thecomputer-readable medium would include the following: a portablecomputer diskette (magnetic), a random access memory (RAM) (electronic),a read-only memory (ROM) (electronic), an erasable programmableread-only memory (EPROM or Flash memory) (electronic), and a portablecompact disc read-only memory (CDROM) (optical). In addition, the scopeof the present disclosure includes embodying the functionality of theexample embodiments of the present disclosure in logic embodied inhardware or software-configured mediums.

Although the present disclosure has been described in detail, it shouldbe understood that various changes, substitutions and alterations can bemade thereto without departing from the spirit and scope of thedisclosure as defined by the appended claims.

1. A method of receiving radio frequency (RF) communications,comprising: receiving an amplitude modulated (AM) signal using a passiveRF receiver circuit; converting the AM signal to a digital output signalusing a comparator; determining whether the digital output signal isvalid or not using a digital signal processing circuit to determine ifthe digital output signal includes a nonce followed by a known value;and upon detection of a valid digital output signal, enabling an activeRF receiver circuit for RF signal processing.
 2. The method of claim 1wherein the passive RF receiver circuit comprises an antenna, a notchfilter, and an AM demodulator device.
 3. The method of claim 1, whereinthe comparator is AC coupled to the passive RF receiver circuit.
 4. Themethod of claim 1, wherein determining whether the digital output signalis valid or not uses one or more coding techniques.
 5. The method ofclaim 1, wherein determining whether the digital output signal is validor not is based at least in part on determining if the digital outputsignal includes a nonce followed by a known value.
 6. The method ofclaim 1, wherein enabling an active RF receiver circuit for RF signalprocessing further includes using active signal modulation techniques.7. The method of claim 1, wherein enabling an active RF receiver circuitfor RF signal processing further includes executing a process inaccordance with a signal received by the active RF receiver circuit. 8.A system for reception of RF communications, comprising: a passive RFcircuit configured to receive an AM signal; a comparator configured toconvert the AM signal to a digital output signal; and a processorcomprising a non-tangible computer readable medium with a set ofinstructions operable to: receive the digital output signal from thecomparator; determine whether the digital output signal is valid basedon a determination of whether the digital output signal includes a noncefollowed by a known value; and upon detection of a valid digital outputsignal, enable an active RF receiver circuit for RF signal processing.9. The system of claim 8 wherein the passive RF receiver circuitcomprises an antenna, a notch filter, and an AM demodulator.
 10. Thesystem of claim 8, wherein the comparator is AC coupled to the passiveRF receiver circuit.
 11. The system of claim 8, wherein the instructionto determine whether the digital output signal is valid comprises one ormore encryption techniques.
 12. The system of claim 8, wherein theinstruction to determine whether the digital output signal is validfurther comprises an instruction to determine if the digital outputsignal includes a nonce followed by a known value.
 13. The system ofclaim 8, wherein the instruction to enable an active RF receiver circuitfor RF signal processing comprises an instruction to use one or moreactive signal modulation techniques.
 14. The system of claim 8, whereinthe instruction to enable an active RF receiver circuit for RF signalprocessing further comprises an instruction to execute a process inaccordance with a signal received by the active RF receiver circuit. 15.An apparatus for reception of RF communications comprising: a passive RFreceiver circuit for receiving an AM signal; a comparator for convertingthe AM signal to a digital output signal; a first digital signalprocessing circuit for determining whether the digital output signal isvalid based on a determination of whether the digital output signalincludes a nonce followed by a known value; and a switch for activatingan active RF receiver circuit for RF signal processing upon detection ofa valid digital output signal.
 16. The apparatus of claim 15, whereinthe passive RF receiver circuit comprises an antenna, a notch filter,and an AM demodulator.
 17. The apparatus of claim 15, wherein thecomparator is AC coupled to the passive RF receiver circuit.
 18. Theapparatus of claim 15, wherein the digital signal processing circuitdetermines whether the digital output signal is valid or not is based atleast in part on determining whether the digital output signal includesa nonce followed by a known value.
 19. The apparatus of claim 15,wherein the active RF receiver circuit comprises an active RF receiverand a second signal processor, the first signal processor consuming lowpower relative to the power consumption of the second signal processor.20. The apparatus of claim 15, wherein the active RF receiver circuitcomprises an RF notch filter.